ci(auth_v2): run auth_v2 tests in a dedicated shard to avoid test_models basename clash

Adding tests/test_litellm/proxy/auth_v2 to the proxy-auth shard collided with proxy/client/test_models.py (both bare test_models, no package __init__), failing collection with an import file mismatch. Run the auth_v2 suite in its own job with the xmlsec1 apt packages instead; the base apt-packages input added earlier is reused.

.github/workflows/test-unit-proxy-auth-v2.yml

@@ -0,0 +1,28 @@
+name: "Unit Tests: Proxy auth_v2"
+
+on:
+  pull_request:
+    branches:
+      - main
+      - litellm_internal_staging
+      - litellm_oss_branch
+      - "litellm_**"
+
+permissions:
+  contents: read
+  id-token: write
+  pull-requests: write
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  proxy-auth-v2:
+    uses: ./.github/workflows/_test-unit-base.yml
+    with:
+      test-path: "tests/test_litellm/proxy/auth_v2"
+      apt-packages: "xmlsec1 libxmlsec1-dev"
+      workers: 2
+      reruns: 2
+      artifact-name: proxy-auth-v2

.github/workflows/test-unit-proxy-auth.yml

@@ -21,8 +21,7 @@ jobs:
   proxy-auth:
     uses: ./.github/workflows/_test-unit-base.yml
     with:
-      test-path: "tests/test_litellm/proxy/auth tests/test_litellm/proxy/auth_v2 tests/test_litellm/proxy/hooks tests/test_litellm/proxy/policy_engine tests/test_litellm/proxy/client"
-      apt-packages: "xmlsec1 libxmlsec1-dev"
+      test-path: "tests/test_litellm/proxy/auth tests/test_litellm/proxy/hooks tests/test_litellm/proxy/policy_engine tests/test_litellm/proxy/client"
       workers: 2
       reruns: 2
       artifact-name: proxy-auth